This invention relates generally to the field of connectors, and more particularly to connectors which may be coupled and uncoupled by hand or which may be uncoupled by pulling apart the connectors with a prescribed force. In one specific application, the invention relates to connectors which may be used to connect air lines and/or electrical signal and power lines for a rail car braking system.
Current braking systems used on most freight trains in the United States are based on a technology that was developed almost one hundred years ago. Such systems rely on the use of pressurized air to both control and power the brakes. In order to supply pressurized air to the rail cars, an air line is provided along each rail car. When the rail cars are connected, each air line is coupled together to form a single air line running the length of the train. The coupling mechanism generally employed to join each air line is commonly referred to as a "gladhand" coupling and has remained substantially unchanged over the last century.
To connect a pair of gladhand couplings, the couplings are abutted adjacent each other and the couplings are rotated in opposite directions until sufficiently engaged. The glandhand couplings each contain a 90 degree bend through which air must travel when passing through the connection. To prevent the couplings from disconnecting when subjected to vibration, some have incorporated a locking device which locks the couplings together after they have been joined.
Although gladhand couplings have been generally successful in coupling air lines of conventional pneumatic braking systems, such systems suffer from significant drawbacks which have prompted the development of newer systems. More particularly, with such pneumatic systems braking time is affected by the speed with which air pressure changes travel along the train. For trains having large numbers of rail cars, a significant delay may be experienced while the compressed air passes the entire length of the train. To compensate for this delay, trains require a longer stopping time and may also be prematurely or overly slowed in order to ensure a safe operating speed.
Recently, a new braking system has been proposed and is referred to as an Electrically-Controlled-Pneumatic (ECP) braking system. The ECP braking system relies on air to power the brakes, but controls actuation of the brakes electronically. Hence, to operate the ECP braking system, each rail car must be provided not only with compressed air but also with an electrical power or signal line. Gladhand couplings are ill-suited for connecting both air and electrical lines since the gladhand couplings are rotated to join the couplings.
It would therefore be desirable to provide methods, systems, and apparatus for coupling various lines, particularly air and/or electrical lines (including both signal and power lines). Such methods, systems, and apparatus should allow such lines to be easily coupled and uncoupled, particularly by hand. In the case of rail cars, it would be desirable to provide connectors which could be coupled without rotating any electrical contacts. It would further be desirable if such connectors could be axially pulled apart at a prescribed force. It would be still further desirable if such connectors would remain connected when subjected to significant vibration. Such connectors should also be hermaphroditic so one connector may be interchangeably connected with any other connector.